Furnace grate



Aug. 4, 1925.

W. WYAND FURNACE GRATE Filed Aug. 28. 1924 Patented Aug. .l, Yi925.,

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FURNACE GRATE.

Application led August 28, 1924. Serial No. 734,669.

To aZZ whom 'it may concern:

Be it linown that l, WILLiAM llivarm, a citizen of the United States, residing at Absecon, in the county of Atlantic and State of New Qlerscy, have invented certain new and useful improvements in Furnace Grates, of which the following is a specilication.

This invention relates io boil-erfurnaces specially adapted `for burning low'grade coal or culrn; and it consists of a franiefor supporting the gratebars or fuel plates, provided with passages for cooling fluidA hereinafter fully described and claimed.

l'n the drawings, Figure 1 is acrossse'ction througha grate and an ash-pit, showing the frame provided with passages forv air. Fig. 2 yis. a plan view of the end portions of the fraine and portions of the fuel plates. Fig. 3 is a side view of a portion of one ofthe deflccting plates drawn to a larger scale. Fig. 4. is a plan view of the saine. Fig. 5 is a cross-section through one of the hollow bars of the fraine show-- ing it modified so that water can be used instead of air for the purpose of cooling it.

The fraine is provided with a series of hollow longitudinal bars 8 arranged parallei to each other. These bars are connected at one end to a hollow front end bar 9 to which a pipe 10 is attached for the supply of cooling fluid under pressure. Air is preferably used, but in sonne cases water may be used, and the construction 1s then modified accordingly.

The rear ends ofthe bars 8 are closed, and they are preferably secured to an end bar 10, which need not be a hollow bar when air is used as the cooling fluid. The bars 8, 9 and 10 inay be forined integral with each other, or they may be formeel separately and secured together in any approved way. Distance pieces 12 are arranged between the longitudinal bars 8 at suitable points, but inay be omitted 1f the fraine is a short one. Any number of frames may be secured side by side.

The longitudinal bars k8 are preferably oval in crosssection, and they have longitudinal ribs 1li at their tops, and shoulders 15 for supporting the grate bars or fuel plates'l. The shoulders may be on the bars, or they inay be. beveled sides of the ribs 14. Upwardly converging air passages 13 are formed between the lower parts of the bars Y 8. The grate bars or fuel plates 16 are of any approved form provided with a multiplicity of sniall air passages 17, and their edges are adapted to rest against the ribs or on the shoulders 15. The bottoms of the longitudinal bars 8 are provided with outlet openings when air is used as the cooling fluid, and these openings may be narrow slots 18 of any suitable length or holes 18 of any suitable size and shape. The bars 8 are integrally-formed, and the lower parts of the` convex sides of the adjacent bars forni the upwardly converging passages or air spx-.ces 13. The air discharged from the outlets 18 is brought in contact with the Tl. outsides of the bars in these spaces 13, and

is heated on its way upward to pass through the small openings of the fuel plates which are supported over the air spaces 13.

The tops of the ribs lil and of the distance pieces 12 are shown flush with the tops of the fuel plates. It is not desirable for the dis-tance pieces to project above the fuel plates as that would interfere with running a poker lengthwise under the fuel in stoking, but the ribs 14 can be of any desired height.

Each longitudinal bar 8 is provided with one or more deflecting devices or plates 20. Each delico-ting plate has a shank 21 which is preferably cast in the metal at the upper part of the bar under the rib 14. The deflecting plate may however be secured in any other approved way so that it depends within the hollow bar. Each deecting plate is provided with a series of tongues 22 bent right and left alternately, and if desii-ed twisted, as shown.

These tongues project in the hollow bars and oblige the cooling fluid to follow a tortuous course. They also deflect all parts of the cooling fluid repeatedly against the sides of the bars, and they increase the area of surface exposed to the cooling fluid.

When air is used as the cooling fluid the fraine is supported in a combustion chainber 24 over a closed ashhpit 25. Air is forced Linder pressure into the front ends of the longitudinal bars 8 so that it cools them, and passes out of them downwardly through their outlet openings 18, and thence upwardly through the air passages 17 of the grate bars, as indicated by the curved arrows in Fig. 1, after being suitably heated by contact with the longitudinal bars and their deflecting plates.

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1llv'hen water is used as the cooling Huid the longitudinal bars 8 have imperforate bottoms Vas shown in Fig. 5, but have the defleeting plates 20 as hereinbefore described7 and the water is let out at the rear ends of the bars 8. These bars 8 can also be used for air, if desired.

l rlhe air to support combustion is forced from the ash-pit upwardly through the passages in .the gra-te bars, but is warmed to la less exten-t than when forced through the longitudinal bars 8.

The air' is forced through the fuel in small streams, and the pre-heating of it facili- .l 4tasthe combustion, and also prevents the bars having also air outlets intheir bottoms,

upwardly converging air spaces"` being formed between the convex lower portions of adjacent bars, which spaces receive the air from the said outlets, and said barshav'- ing also means for supporting fuel plates over the said air spaces. l

3. The combination, with a frame provided with tubular ,bars as set forth in claim 2, of a closed ash-pit below the frame" so` that the air forced through the said bars is constrained to pass upwardly through the said converging spaces between them.

4. In a furnace grate, aframeprovided with tubular bars arranged parallel to each other and having convex adjacent side p0rtions which form an `air passagejwhich widens out upwardly and downwardly from gli the middle of the convex side portions," said l bars'having also air outlets at'their bottoms and ineens for supporting a fuel` plate at their upper parts over the said `air passage to" which air is supplied from the said`outlet`s.= affixed* my` ln testimony whereof I have signature.

WILLIAM WYAND.: 

